WASHINGTON — One week after the Obama administration said it would comply with a federal appeals court ruling ordering it to make public portions of a Justice Department memo that signed off on the targeted killing of a United States citizen, the administration is now asking the court for permission to censor additional passages of the document.

In the interim, the Senate voted narrowly last week to confirm David Barron, the former Justice Department official who was the memo’s principal author, to an appeals court judgeship. At least one Democratic senator who had opposed Mr. Barron over the secrecy surrounding his memo voted for him after the administration said it would release it.

The 41-page memo, dated July 16, 2010, cleared the way for a drone strike in Yemen in September 2011 that killed Anwar al-Awlaki, an American citizen accused by intelligence officials of plotting terrorist attacks. The American Civil Liberties Union and The New York Times are seeking the memo’s public disclosure in lawsuits under the Freedom of Information Act.

The Justice Department said it would soon disclose a version of the memo with the additional passages it wants to keep redacted blacked out. It said the additional passages discussed classified facts, not legal reasoning.

In January 2013, a Federal District Court judge ruled that the government could withhold the memo from the public entirely. But this April, a panel of the United States Court of Appeals for the Second Circuit, in New York, ruled that the government must make public portions of the memo that lay out legal analysis, though not facts based on classified intelligence.

The Second Circuit’s opinion specified which passages of the memo should be disclosed and which should be redacted. But in a new court filing, Sarah Normand, an assistant United States attorney, said that the sections of the memo that the court had designated for public release contained further information that should be exempt from disclosure.

“Some of the information appears to have been ordered disclosed based on inadvertence or mistake, or is subject to distinct exemption claims or other legal protections that have never been judicially considered,” Ms. Normand wrote.

The Justice Department asked to keep its entire motion seeking additional redactions secret, but on Wednesday the court issued a five-page order denying that request and saying that as much of the motion as possible would have to be made public.

The order also recounted new details about several previous rounds of then-secret negotiations between the court and the government, dating back to February, over what would be redacted.

Last week, the administration said that Solicitor General Donald B. Verrilli Jr. had decided to release the memo but would file a limited appeal to keep some facts redacted in the final public version of the court’s ruling. Among the information redacted in the ruling is the identity of an agency, in addition to the Defense Department, that had an operational role in the drone strike that killed Mr. Awlaki. Although it is widely known that the C.I.A. operates drones, including from a base in Saudi Arabia, and that it participated in the operation that killed Mr. Awlaki, the Obama administration still officially treats that information as secret.

Mr. Verrilli’s decision to release the memo changed the politics of Mr. Barron’s confirmation fight. In particular, Senator Mark Udall, Democrat of Colorado, who had said he would oppose Mr. Barron because of the administration’s secrecy, said he would support him.

Mr. Udall had focused on obtaining for the public the government’s legal reasoning. In a statement on Wednesday, Mr. Udall said the administration had told him as well that its additional “redactions to the memo would focus on still-classified information — not the legal reasoning itself.” He added, “I intend to hold the White House to its word.”

A version of this article appears in print on , on Page A24 of the New York edition with the headline: U.S. Seeks to Censor More of Memo That Approved Drone Strike on American. Order Reprints | Today’s Paper | Subscribe